With the progress of computer graphics technology in recent years, game devices and simulation devices have come into wide, general use. Among the game devices, the popularity of gun shooting games, wherein targets (enemies) are shot down, remains strong. Generally, this game device comprises a gun unit, CPU for graphics processing, a monitor, etc., and implements the processing of shooting down the enemies on the monitor according to the signal from the gun unit operated by the player.
As a typical example of a conventional gun shooting game, there is "Virtual Cop" (trademark) manufactured by SEGA ENTERPRISES, LTD. The object of this game is to compete for scores by shooting down the enemies which appear in the imaginary three-dimensional space on the display using a gun unit. In this game, the enemies appear on the display in a predetermined position and in a predetermined timing, whereby the player operates the gun unit with these enemies being the target. That is, the player shoots down the enemies which are indicated each time in a predetermined position and timing on the display. Further, when the player aims the gun unit toward an enemy, the viewpoint on the display approaches the enemy, thus, the enemy is largely indicated on the display.
Of the other conventional gun shooting games, there is one in which the enemies move on the screen according to the attacks made by the player. In this game, when the player attacks an enemy, a prescribed moving route is selected at the branch point of the predetermined moving route, and the enemy moves according to this selected moving route. Similar to the enemy movements, the viewpoint also moves in predetermined directions.
However, the above conventional image generating devices held the problems indicated below.
Foremost, since the movement of the viewpoint was uniform, the changes on the screen were limited. The two types of games mentioned above were both of which the viewpoint-moved in predetermined directions. Therefore, if the player repeatedly played the game, a similar screen would be repeatedly indicated each time, thus, making the changes in the game a limited one.
Secondly, it was difficult to capture the enemies, etc., from a position of an optimum viewpoint. In conventional image generating devices, the viewpoint moved uniformly against the enemies from a predetermined direction. Therefore, it was not possible to move the viewpoint to an optimum position against the enemies according to the changes of the enemies, thus, making it difficult to indicate an appealing screen desired by the player.
Thirdly, due to the movement of the enemies being uniform, a dull game development was being repeated. As mentioned above, in the conventional game devices of gun shooting, the enemies made predetermined movements and could not help but make the game development a dull one.
The present invention was made in consideration of the problems mentioned above, and a first object of the present invention is to provide an image generating device and an image generating method capable of actualizing a screen with changes by implementing various viewpoint movements.
A second object of the present invention is to provide an image generating device and an image generating method capable of indicating an appealing screen by implementing an optimum viewpoint movement according to the game development.
A third object of the present invention is to provide an image generating device and an image generating method capable of actualizing a game development with abundant changes by giving variety to the movement of the enemies.